“After an exhaustive search effort utilizing a significant number of crews and assets, we’ve come to the very difficult decision to suspend this search,” Coast Guard Capt. Sean Mahoney said in a statement.

“Our thoughts are with the family and friends of Mr. Ruden, and my deepest sympathy goes out to them,” said Mahoney, commander of Coast Guard Sector San Diego.

The official search area was about 600 square miles and stretched from La Jolla north to San Mateo, and 17 miles out to sea.

Ruden’s boat, with the engine running, was found Tuesday morning about 10 miles northwest of La Jolla.

Mahoney said the Coast Guard resources for the search included four helicopters, two from San Diego and two from Los Angeles, along with two cutters and several other boats.

Oceanside Harbor Police in boats and a U.S. Customs and Border Protection aircraft crew also searched, and the FBI was investigating.

Two boats carrying volunteers also headed out of Oceanside on Wednesday to help scan the ocean, Dunphy said.